Terrorist Group Claims Kidnapped 300 Teens

(CNN) - Three weeks after the kidnapping of nearly 300 high school girls in Africa's most populous country, the Nigerian government is no closer to finding them.

In a video that surfaced Monday, the leader of the Nigerian terrorist group, 'Boko Haram,' acknowledged kidnapping hundreds of teenage girls from their dorms in a remote part of northern Nigeria. The man called the young students slaves. He says he would sell them and threatened to attack more schools. This is the first time Boko Haram - which means 'western education is sinful' - has claimed responsibility for the April kidnapping.

People in Nigeria and abroad continue to put pressure on Nigeria's government to find the girls.

"They have been promising us that these girls would be found but up to today, up to this moment i am still talking, says Martha Yarama Ndirpaya, Mother of missing girl.

But it may already be too late. Some local leaders in Nigeria say some of of the girls may have already been sold as sex slaves in neighboring countries. Some of the girls managed to escape, but nearly 300 are still missing. There are reports some of those students were sold for as little as $12.